Many aspects of language comprehension are closely time-locked to linguistic input. Thus psycholinguists have increasingly relied upon on-line experimental methods that provide fine-grained temporal information about language processing, e.g., monitoring eye movements during reading. However, most standard methods do not allow for continuous monitoring and cannot be easily adapted to natural situations. We are using the sensori-motor laboratory to monitor eye movements as subjects follow spoken instructions to manipulate objects (e.g., ``Put the apple that's on the towel in the box.''). With well-defined tasks, eye movements can illuminate the rapid mental processes that underlie spoken language comprehension. This approach can help explore topics ranging from recognition of spoken words to conversational interactions during cooperative problem solving. Preliminary experiments showed that participants process instructions incrementally, making saccadic eye movements to objects immediately after hearing relevant words in the instructions. When asked to touch one of four blocks differing in marking, color, or shape, with instructions such as ``Touch the starred yellow square,'' subjects made an eye movement to the target block an average of 250 ms after the end of the word that uniquely specified the target with respect to the visual alternatives (e.g., after ``starred'' if only one block was starred; after ``square'' if there were two starred yellow blocks). With more complex instructions, subjects made informative sequences of eye movements to objects relevant to establishing reference (e.g., ``Put the five of hearts that is below the eight of clubs above the three of diamonds.'').